The road to credit hell is paved with balance transfers! Especially if you don’t have either the income or the discipline to pay it off before the interest-free grace period ends. Ask yourself why you didn’t plan in advance to have money to contribute to your Roth IRA if its suddenly so important?
I wouldn’t take this route. Keep your credit balances at zero, and set up a Roth at a place like Vanguard or Fidelity and have them take an automatic $500/month for your 2020 contribution. (You aren’t losing a deduction if you don’t make a contribution for 2019 –you’re only losing one year’s growth.) If you squirm at the idea of a $500/month automatic contribution in the year ahead, it means you’ll never get balance transfer cash advance paid off in a year!! And you’ve then answered your own question!